Antalya city, located along the Turkish Mediterranean coast, lacked a proper sanitation system till 1996. An integrated water & wastewater project has been implemented to protect groundwater resources used for drinking and seawater quality. The project involved collection, treatment and final disposal of effluents by a deep sea outfall system. A current research project has been realized to evaluate performance of Antalya Sea Outfall. Seasonal in-situ measurements and bacteriological monitoring studies have been realized. The discharged wastewater plume is observed to be submerged in summer and to reach sea surface in winter condition. The results of the monitoring program exhibit considerable spatial and temporal variations. The resultant total and fecal coliform numbers comply well with the Turkish Standards for the use of coastal and sea water for recreation.